If there was any doubt about the popularity of Apple’s iPad, doubt no more.

ABI Research estimates that iPad users have cumulatively downloaded three billion applications since the launch of the iPad in 2010. The iPhone took almost two years to reach the same download milestone, whereas the iPad reached it in almost a year and a half. Android tablets, in comparison, have only downloaded around 440 million apps so far.

“Discounting all those apps that were originally developed for Android smartphones, Android still trails greatly behind the iPad in terms of its tablet app offerings,” ABI Research Associate Lim Shiyang said. “Many Android tablets in the market are still using older versions of Android, which disadvantages users from enjoying the better effects of apps produced from more advanced software development kits.”

The iPad’s strength lies in it having a larger number of iPad-specific apps. Its apps are also considered to be of higher quality than Android tablet-specific apps.

Things are looking up for Android tablets in the future, however, with the impending launch of Android 4.0, Ice Cream Sandwich. The actual hardware of Android tablets is catching up to the iPad as well with devices like the Amazon Kindle Fire.

When it comes to smartphones, however, Android is still the clear winner. Annual Android app downloads for smartphones are expected to hit 58 billion by 2016. Apple’s iPhone is only expected to hit 27 billion downloads in the same timeframe.